how to fix the computer?

My computer is hang, i check the fan and i clean it. That is working, but that computer still hang. I detached the memory, and try to clean the dust in memory slot. After that problem is resolved, i got my LAN card doesn't connected to other computer. Oh, i see problem is on the moor.

Don't worry mysdiana, i usually fix my own computer, but i cannot improve if one computer component is broken. Several days ago, i had to disassemble my computer desktop. And, i see my VGA fan does not rotate so i separated VGA card and the fan. Then, once cleaned and re-installed VGA fan rotates back. Now, my computer can be used and did not hang at all.
Thank you for dropping by in my discussion.

I also make mistakes, discuss how to fix the computer in the interest mylot.com. Should be interest in computers or computer if i want to have people visit this discussion. But, i cannot move the discussion because that discussion has been already made and cannot be changed.